Photosynthesis

• Photosynthesis is the process by which plants make carbohydrates for their food
• Plants grow best in rainforests
• Van Halmont was interested in what made the plant grow
• Van Halmont thought everything was made of water
• Van Halmont started his experiment by weighting the willow tree and the mass of the soil
• Van Halmont provided it with water for the next 5 years
• In Van Halmont's experiment the mass of the willow tree increases by 73 kg
• In Van Halmont's experiment the mass of the soil decreased by 60 grams
• Stephen Hales discovered a portion helped the plant to grow and survive
• Jan Ingenhousz showed plants take in CO2 from the air when there is light
• Plants have large surface area to produce its food
• We can test for starch with an iodine solution
• The colour of an iodine solution is brown
• When we add iodine solution to starch it turns blue-black
• Chloroplasts are green because of chlorophyll
• Chlorophyll prevents us from seeing colour change when testing for starch
• By dipping a leaf in boiling water for 30 sec we can get its cells dead and further reaction
• Ethernol dissolves chloroplasts
• Leaf is handled with forceps
• A plant with no starch is known as a de-starched plant
• A plan can be de-starched by putting it in dark for 2 to 3 days
• To test light impact on leaf or plant you need to wrap one leave with aluminium foil while the other with a clear plastic bag
• Soda Lime absorbs CO2
• Sodium Hydrogen carbonate releases CO2
• co2 + h20 = c6h12o6 + o2
• Plants need sunlight to make food
• Plants also need chlorophyll to make their food
• First water is used to kill the cells in the leaf and prevent further reaction
• Second water is used to boil the ethornal in the test tube
• Third water is used to make the leaf softer